"None shall pass but shadows, returning to the darkness." – Heartless Prophecy.
. . .
His eyes mirrored the sea. Clear blue and subtly misty, they would sometimes hold storms inside them. Of course, one would notice the storm perhaps a little too late; one would only notice the storm inside Sora after it had wreaked havoc. It wasn't like Sora wanted to reflect tempests in his sky eyes, but what choice did he have? He had learned—albeit the hard way—that the darkness was a part of light and vice versa. Roxas would always be a part of him—he had already been a part of Sora even before he himself turned into a Heartless. And now that Sora accepted the darkness, the lines that were so clear had already faded before he even knew that they had long disappeared.
"So…Raaaaa!" It was her; red hair that sometimes faded to white, a bright smile that sometimes faded to a soft smirk and innocence and naivety that more often than not faded to some kind of silent manipulation. Kairi. Namine. KAIRI.
"Sora," She was already out of breath, but a smile was plastered on her bright face, "All day you were just sitting here and staring out to the sea."
"Kairi," He responded with a half-second delay, "Do you ever wonder about the worlds beyond ours?"
"Always, Sora. Always. We've explored them, saved them. Rescued the people in them." She took a seat beside him on the warm sand. Kairi did not know where he was going. Sora had been this serious ever since he got back, but this time, she knew it was different. How he was different, she did not know, but Kairi trusted her intuition.
When he didn't reply and just looked at her, Kairi spoke again, "You've been staring at the seabed for hours now. Why, Sora?" Did he somehow find a new world? Was the evil returning? Or did Sora turn into that darkness he had always been fighting?
"It's just…" The sea tricked him. The ocean showed him a world where everything was monotone and mundane. The sights and sounds were all black and white noise. And, it was as if he was there…yet, not. There were a pair of headphones, too, and Sora swore he could almost hear the music. A crescendo of music that turned to noise and noise that turned to music. If Sora dipped his hand into the water, would he be transported to the foreign world inside the sea?
"…Sora?" He had told her he would just swim for a bit, and she followed him into the water. The waves danced between them and the air was scented with the comforting smell of salt. But when Kairi closed her eyes to just relax, strange music began playing. And the music frightened her, "SORA!"
. . .
He could still hear Kairi's voice, and her voice urged him to come back. But he chose to stay inside. Sora chose to get lost inside the water that wasn't. He was inside; in between the molecules, and it was as if he was dissolving. Sora couldn't say if it was a pleasant feeling or not, but it was certainly…refreshing. It wasn't like the time darkness consumed him; it was just nothingness…The water made him fly; made him float; and he was closer to the world inside it than he had ever been.
The streetlights appeared in front of him, blinking and shining red, green, yellow. Faceless figures waltzed pass him, as if he was just air. But he didn't feel like a ghostly apparition; Sora felt real. Realer than he had felt ever since he destroyed Xemnas. And so, Sora followed the music that led him there. Perhaps if he would be able to locate the source, he would be able to face himself and face his own fears. This place, after all, was a place beyond good and evil. The place beyond the sea.
. . .
"SORA! SORA, WHERE ARE YOU?" Kairi shrieked, thrashing at the waves. The music had disappeared—and she was thankful for that—but along with it, Sora evaporated as well. Where he had gone to, she did not know and frankly, she did not know where to look. Kairi then resurfaced from the water as she ran towards Riku's place.
She then spotted the silver-haired male, and dashed quickly towards him. But all he did was stare at her blankly. He then shifted his gaze to something beyond her; the sea.
"RIKU! RIKUUUUU…!" She grabbed a fistful of his silver hair, forcing him to look at her. He did not. Kairi felt fear at the pit of her stomach, but she pushed the feeling aside and shouted at her friend, "Riku, you have to help me! Sora…He's gone! RIKU!"
But Riku just pushed her aside, and once he was past her, he turned into thick, grey smoke. Destiny Islands then titled backwards as Kairi's perception of her world shifted. She was slipping, she knew, but there was nothing to hold on to. Sora was gone, Riku was gone. Everyone and everything she had cared for disappeared in the blink of an eye. So she let herself slip into the sea—and into the world inside it—for Kairi had nothing to lose; she had already lost everything.